the company said it was willing to pay 20% over boovalue to uy back its stock. th's twi the lim it eviously set. that increase helped push both the "a" and "b" shares of berkshire higher. the high-priced "a" closed at $134,000; the "b" shares finished at $89.32. both were up 2.4% to their highest price since october. global construction and mining equipment maker joy global struck profit growth in the latest quarter even as the company expects big equipment spending to fall next year. the company earned 2.5 cents per share, well above last year and estimates. the coany'buyout le- tourneau helped improve its bottom line. joy global's muted outlook for next year didn't hurt its shares; they were up 4%. fellow big equipment maker caterpillar gained 0.7%. four of the five most actively traded exchange traded products were up. the lone loser was the nasdaq 100 tracking fund, slipping 0.2%. and that's tonight's "market focus." >> susie: tomorrow on "n.b.r.": nearly half of baby boomers say they're not ready for retirement. tomorrow, we'll show you one couple who are r